The scope and mechanism of cycloaddition of unsaturated molecules to photochemically excited carbon-nitrogen double bonds will be determined. Specifically, the photochemical reactivity of molecules containing the keto imino ether chromophore with electron rich, electron neutral, aromatic, and electron poor olefins, acetylenes, dienes, imines, and imino ethers will be explored. Multiplicity and configuration of excited states, the effect of solvents, and the importance of biradicals, electron transfer, and exciplexes will be determined. The reaction should be of synthetic importance for the preparation of azabicyclics, azetidines, azetines, and benzoazepines. The benzoazepines are structurally related to two important tranquilizers, Diazepam (Valium) and Chlorodiazepoxide (Librium). Cycloadditions of olefins to thiazolines might be a useful synthetic route to penicillin derivatives.